Turbine engine blades typically comprise an airfoil portion having concave and convex sides which extend upwardly from a platform portion below which a root portion is disposed. The platform portion extends transversely of the airfoil portion and may have an arcuate profile. The root portion of the blade is normally attached to a rotor disk. Further, an outer shroud portion may extend transversely across the airfoil portion at the end of the airfoil portion opposite the root portion. The shroud portion has an arcuate profile (e.g., a circular arc profile). Because of the arcuate profile of the platform and shroud portions as well as their transverse orientation relative to the airfoil portion, previous cathode assemblies useful to electrochemically machine turbine blades were unable to simultaneously machine the airfoil portion, platform portion, and the shroud portion, especially when the platform portion and/or the shroud portion have negative angles relative to the first direction of movement of the electrode.
U.S. Pat. No. 4,256,555 to Wilson et al, issued Mar. 7, 1981 illustrates an electrode assembly for electrochemically machining an airfoil portion and platform portion of a gas turbine engine blade. The assembly includes a pair of electrodes moveable relatively toward each other and toward a workpart, or airfoil, therebetween. The electrodes simultaneously machine the workpart and the platform directly above the root portion. The electrodes are moveable relatively toward the workpart in a first direction toward the workpart. However, by utilizing such an electrode assembly, it is impossible to simultaneously electrochemically machine the airfoil, platform portion and a shroud portion, especially when the platform portion and shroud portion have an arcuate profile and negative angles relative to the direction of electrode movement.